An AI programmer accidentally develops an AI program called Cho Sang Shin, which will identify trashy humans, and she uses it to save people who are in difficult relationships.

Nam Se-Hee is a single man in his early 30's. He has chosen to not marry. He owns his home, but he owes a lot on his mortgage. Yoon Ji-Ho is a single woman in her early 30's. She does not own a home and envies those that do. She has given up on dating due to her financial struggles. Yoon Ji-Ho begins to live at Nam Se-Hee’s house. They become housemates.